#include <bits/stdc++.h>
using namespace std;
using ll = long long;

using matrix = vector<vector<ll>>;

matrix prod(matrix a, matrix b) {
  int n = a.size();
  matrix ans(n, vector<ll>(n));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      // ans[i][j]
      for (int k = 0; k < n; k++) {
        ans[i][j] += a[i][k] * b[k][j];
      }
    }
  }
  return ans;
}

struct RMQ {
  const matrix INF = {{1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}};
  int n;                                // 葉の数
  vector<matrix> dat;                   // 完全二分木の配列
  RMQ(int n_) : n(), dat(n_ * 4, INF) { // 葉の数は 2^x の形
    int x = 1;
    while (n_ > x) {
      x *= 2;
    }
    n = x;
  }
  void update(int i, matrix x) {
    i += n - 1;
    dat[i] = x;
    while (i > 0) {
      i = (i - 1) / 2; // parent
      dat[i] = prod(dat[i * 2 + 1], dat[i * 2 + 2]);
    }
  }
  // 半開区間[l,r)
  // the minimum element of [a,b)
  matrix query(int a, int b) { return query_sub(a, b, 0, 0, n); }
  matrix query_sub(int a, int b, int k, int l, int r) {
    if (r <= a || b <= l) {
      return INF;
    } else if (a <= l && r <= b) {
      return dat[k];
    } else {
      matrix vl = query_sub(a, b, k * 2 + 1, l, (l + r) / 2);
      matrix vr = query_sub(a, b, k * 2 + 2, (l + r) / 2, r);
      return prod(vl, vr);
    }
  }
};

void solve() {
  int n, q;
  cin >> n >> q;
  string s;
  cin >> s;
  s = "+" + s;
  RMQ seg(n / 2 + 10);
  for (int i = 0; i < s.size(); i += 2) {
    matrix now(4, vector<ll>(4, 0));
    char op = s[i], tf = s[i + 1];
    if (op == '+' and tf == 'T') {
      now[1][1] = 1;
      now[0][1] = 1;
    } else if (op == '*' and tf == 'F') {
      now[0][0] = 1;
      now[1][0] = 1;
    } else if (op == '^' and tf == 'T') {
      now[0][1] = 1;
      now[1][0] = 1;
    } else {
      now[0][0] = 1;
      now[1][1] = 1;
    }
    if (tf == 'T')
      now[2][1] = 1;
    else
      now[2][0] = 1;
    now[1][3] = 1;
    now[2][2] = 1;
    now[3][3] = 1;
    seg.update(i / 2, now);
  }
  for (int i = 0; i < q; i++) {
    int l, r;
    cin >> l >> r;
    l /= 2;
    r--;
    r /= 2;
    matrix mat = seg.query(l, r + 1);
    ll ans = mat[2][1] + mat[2][3];
    cout << ans << endl;
  }
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cout << fixed << setprecision(20);
  int CNT = 1;
  for (int i = 0; i < CNT; i++)
    solve();
}